With social networks or any EU startup problem is you have to deal with different languages right at the start.
Being US startup with English only you have access to 300m people right away.
There were country specific social networks but then all cool kids were on FB so everyone moved there.
The same with LinkedIn, our country specific business social network closed down finally last year. First 3-5 years it was growing then everyone moved to LinkedIn so that network was ghost town for 15 years someone kept it alive just in case but seems like they stopped wasting money.
I think the language problem will become less of a problem in the future due to (1) more (young) people living in citys and (2) all young people in cities speaking english. At least compared to previous generations imo. This could be my subjective view based on luxembourg, netherlands, and visiting other european cities.
Don't overestimate "young people speaking english" especially with current demography you still need to tap ones that are excluded from English as there will be much more of those.
I do see opportunities with LLMs as making all kind of platforms language agnostic - you should be able to write your own language and read your own language even if other person is from different country using different language.
Being US startup with English only you have access to 300m people right away.
There were country specific social networks but then all cool kids were on FB so everyone moved there.
The same with LinkedIn, our country specific business social network closed down finally last year. First 3-5 years it was growing then everyone moved to LinkedIn so that network was ghost town for 15 years someone kept it alive just in case but seems like they stopped wasting money.